Currently, there are a variety of systems that send redundant data streams over different networks in order to provide failover in case one of the networks fails. This way, if a network fails, the data stream will still be received and minimal disruption to the data stream will occur.
Other systems identify multiple routing paths for a data stream. When one routing path fails or drops below a certain quality of service, the data stream is then routed down a second path. For example, U.S. Patent Application Publication 2007/0177579 describes a system that evaluates the quality of service for a first network path. The system sends data on redundant data paths. If the quality of service of the first network path falls below a predefined level, the receipt of the data stream is switched from the first network path to the second network path. Likewise, Patent Application Publication 2006/0203805 describes a system that evaluates the quality of service of multiple network paths and then routes a data stream down the network path with the higher quality of service.
The problem with these approaches is that they are not optimized to address the deficiencies that are unique to sending audio streams over packet-based communication systems. The most common being impairment is due to intermittent packet loss and packet delay. In addition, these systems fail to utilize factors such different audio packet durations, packet timestamps, packet sequence numbers, multi-vendor encoding standards, and analysis of acoustic properties of audio packets.